Semiconductor device protective structure and method for fabricating the same

ABSTRACT

The present invention provides a semiconductor device protective structure. The structure comprises a die with contact metal balls formed thereon electrically coupling with a print circuit board. A back surface of the die is directly adhered on a substrate and a first buffer layer is formed on the substrate. The substrate is configured over a second buffer layer such that the second buffer layer substantially encompasses the whole substrate to decrease damage to the substrate when the side of the substrate is collided with an external object.

RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 11/175,420, filed Jul. 6, 2005 now U.S. Pat. No. 7,176,567.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a semiconductor device structure, and moreparticularly to a semiconductor device protective structure and methodfor fabricating the same, the semiconductor device structure can avoidthe die or substrate from cracking due to the side of the die orsubstrate collided with an external object.

2. Description of the Prior Art

Typically in the electronic component world, integrated circuits (IC's)are fabricated on a semiconductor substrate, known as a chip, and mostcommonly are made of silicon. The silicon chip is typically assembledinto a larger package which serves to provide effective enlargement ofthe distance or pitch between input/output contacts of the siliconmaking it suitable for attachment to a printed circuit board, and toprotect the IC from mechanical and environmental damage. With the trendmoving to more and more features packed into decreasing productenvelopes, utilizing ever smaller electronic components to improve uponsize and feature densification a constant and formidable challenge ispresented to manufacturers of consumer and related articles.

Chip scale packages (CSP) were developed to provide an alternativesolution to directly attached flip chips devices. These packages (CSP)represent a new miniature type of semiconductor packaging used toaddress the issues of size, weight, and performance in electronicproducts, especially those for consumer products such as telephones,pagers, portable computers, video cameras, etc. Standards have not yetbeen formalized for CSP, and as a result, many variations exist, andseveral of which are described in “Chip Scale Package”, cited above. Ingeneral, the chip is the dominant constituent of a CSP with the area ofthe package, being no more than 20% greater than the area of the chipitself; but the package has supporting features which make it morerobust than direct attachment of a flip chip.

As shown in FIG. 1, it is a side view of a flip chip device 100according to prior art. The flip chip 100 includes a die 102 with metalpads 105 that typically has a conventionally fabricated IC devicestructure. The die 102 has a plurality of electrical contacts 104, suchas redistribution layer (RDL) trace. Bumps 103, such as solder balls,are formed on the electrical contacts 104. A protection layer 106 coversthe electrical contacts 104 to expose the electrical contacts 104 forallowing the solder balls 103. Moreover, a protective film 101 isapplied to the bottom surface of the die 102.

The protective film 101 may be formed from any suitable material. Forexample, the protective film 101 may be formed from a plastic materialor epoxy. This epoxy is commonly also used as a glob top material forchip-on-board applications that protects the die 102 and wire bonds. Theprotective film 101 may have any thickness that substantially preventschipping during the dicing operation and is suitable for the particularapplication. For example, the protective film 101 may have a thicknessthat allows laser marking of the thick film without the laserpenetrating the thick film. Preferably, the protective film 101 isbetween about 1.5 and 5 mils. Most preferably, the protective film isbetween about 2 and 3 mils.

Furthermore, the substrate of the flip chip or semiconductor device(such as integrated circuit's) has a friability property such that thesedevices are easily result in cells edge of the wafer fail due to thesubstrate being lateral damage or cracking owing to the side of the dieor the substrate colliding with an external object or applied by anlateral external force. Therefore, the reliability or the life time ofthe flip chip or semiconductor device will be decrease.

In view of the aforementioned, the present invention provides animproved semiconductor device structure to overcome the above drawback.

SUMMARY OF THE INVENTION

To achieve the foregoing and other objects and according to the purposeof the present invention, a semiconductor device protective structureand method for fabricating the same are disclosed.

The semiconductor device protective structure of the present inventioncan avoid the die or substrate from cracking due to the side of the dieor substrate collided with an external object.

The semiconductor device protective structure of the present inventionmay avoid the die or substrate from cracking by a buffer layersubstantially encompassing the die or substrate to decrease damage tothe die or substrate when the side of the die or substrate is collidedwith an external object.

The present invention provides a semiconductor device protectivestructure. The structure comprises a die having a plurality ofelectrical contacts on a first surface of the die. A plurality ofconductive balls coupled to the contacts. A protective layer is coveredthe plurality of electrical contacts and the dielectric layer to exposethe electrical contacts for allowing the conductive balls electricallycoupling with an external part. A second surface of the die is directlyadhered on a substrate. A first buffer layer is formed on the substrateand adjacent to the die. The substrate is configured over a secondbuffer layer such that the second buffer layer substantially encompassesthe whole substrate, whereby to decrease damage to the substrate whenthe side of the substrate is collided with an external object.

Wherein the substrate includes slope sidewall slots formed therein.Wherein the second buffer layer is refilled into the slope sidewallslots. Wherein a depth of the slope sidewall slot is substantially thesame with a thickness of the substrate.

In another aspect, the present invention discloses a method formanufacturing a semiconductor device protective structure. The methodcomprises providing a plurality of dice with a plurality of conductiveballs formed thereon electrically coupling with an external part. Next,the plurality of dice are adhered over a substrate. A first buffer layeris formed over the substrate and adjacent to the dice to expose theplurality of conductive balls. A partial of the substrate is removed toform a plurality of slots and substantially aligned to the first bufferlayer. Finally, a second buffer layer is formed over the substrate andfilled with the plurality of slots.

The above-mentioned method further comprises a step of sawing and/oretching the substrate along about the substantially center of the slotsinto a plurality of individual semiconductor devices protectivestructure.

Wherein the slots includes slope sidewall slots. Wherein a depth of theslope sidewall slot is substantially the same with a thickness of thesubstrate.

In yet another aspect, the present invention discloses a method formanufacturing a semiconductor device protective structure. The methodcomprises providing a substrate having a plurality of dice with aplurality of conductive balls formed thereon. Next, a backside surfaceof partial substrate is removed to form a plurality of slots. A bufferlayer is formed over the substrate and filled with the plurality ofslots.

The above-mentioned method further comprises a step of sawing and/oretching the substrate along about the substantially center of the slotsinto a plurality of individual semiconductor devices protectivestructure.

The buffer layer may reach the function to avoid the dice or substratefrom damaging when the side part of the dice or substrate collides withan external object.

BRIEF DESCRIPTION OF THE DRAWINGS

The above objects, and other features and advantages of the presentinvention will become more apparent after reading the following detaileddescription when taken in conjunction with the drawings, in which:

FIG. 1 is a diagrammatic side view of a flip chip device according tothe prior art.

FIG. 2 is a schematic diagram of a semiconductor device protectivestructure according to the present invention.

FIG. 3 is a schematic diagram of a semiconductor device structure.

FIG. 4 is a schematic diagram of a semiconductor device protectivestructure according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Method and structure for protecting a semiconductor device (such asintegrated circuit) or a substrate during and after a dicing operationare described below. In the following description, numerous specificdetails are set forth in order to provide a thorough understanding ofthe present invention, and the scope of the present invention isexpressly not limited expect as specified in the accompanying claims.

In one embodiment, the present invention discloses a method formanufacturing a semiconductor device protective structure. The methodcomprises providing a substrate, such as a silicon wafer, having aplurality of dice with a plurality of conductive balls formed thereon.Next, portions of the backside surface of the substrate are removed toform a plurality of slots 206. A buffer layer is formed over thesubstrate and filled within the plurality of slots 206. The buffer layercomprises BCB, SINR (Siloxane polymer), epoxy, polyimides or resin.Moreover, a step of removing the partial substrate is performed bysawing or etching.

The above-mentioned method further comprises a step of sawing and/oretching the substrate along about the substantially center of the slots,thereby separating the substrate into a plurality of individualsemiconductor devices with protective structure 200, shown as FIG. 2.The buffer layer may reach the function to reduce the die from beinglateral damage due to less contact area of the die when the side part ofthe dice collides with a lateral external object.

As shown in FIG. 2, it is a side view of a semiconductor deviceprotective structure 200 according to the present invention. Thesemiconductor device protective structure 200 includes a die 202 withmetal pads 205. The die 202 has a plurality of electrical contacts 204,such as RDL trace. Bumps 203, such as solder balls, are formed on theelectrical contacts 204. A protection layer 207 covers the electricalcontacts 204 to expose the electrical contacts 204 for allowing thesolder balls 203.

The die 202 includes a plurality of slots formed inwardly from thebackside surface of the die 202 into partial of the die 202. Moreover, abuffer layer 201 is applied to the bottom surface of the die 202 andrefilled into the slots for protection. Because the slots 206 performedby sawing or etching method is filled with BCB, SINR (Siloxane polymer),epoxy, polyimides or resin, the less contact area of the die 202 isarrived. Therefore, the buffer layer 201 may reach the function toreduce the die 202 from being lateral damage due to less contact area ofthe die 202 when the lateral part of the dice 202 collides with anexternal object or applied by an lateral external force.

As shown in FIG. 3, it is a side view of a semiconductor devicestructure 300. The semiconductor device structure 300 comprises a die305 with metal pads 306 and contact metal balls 307 formed thereonelectrically coupling with a print circuit board (not shown). Aprotection layer 309 covers the electrical contacts 308 to expose theelectrical contacts 308 for allowing the contact metal balls 307.

A backside surface of the die 305 is directly adhered on a substrate 302through an adhesive layer 304 and a first buffer layer 303 is formed onthe substrate 302. The first buffer layer 303 is formed adjacent to thedie 305. It should be note that the dimension of the substrate 302 islarger than the one of the die 305. The substrate 302 is configured overa second buffer layer 301. The substrate 302 may be damaged or crackedwhen the side of the substrate 302 is collided with an external objector applied by an external force due to lack of protection of the secondbuffer layer 301. Therefore, the die 305 may be peeled from thesubstrate 302, the reliability and the life time of the semiconductordevice structure 300 will be decreased.

In another aspect, the present invention discloses a method formanufacturing a semiconductor device protective structure. The methodcomprises providing a plurality of dice with a plurality of conductiveballs formed thereon electrically coupling with an external part. Next,the plurality of dice are adhered over a substrate. A first buffer layeris formed over the substrate to expose the plurality of conductiveballs. A partial substrate is removed to form a plurality of slotssubstantially aligned to the first buffer layer. Finally, a secondbuffer layer is formed over the substrate and filled with the pluralityof slots.

The above-mentioned method further comprises a step of sawing and/oretching the substrate along about the substantially center of the slots,thereby separating the dice into a plurality of individual semiconductordevices with protective structure 400, shown as FIG. 4.

In the embodiment, the semiconductor device protective structure 400according to the present invention comprises a die 405 with contactmetal balls 407 formed thereon electrically coupling with a printcircuit board (PCB) or external parts (not shown). A dielectric layer410 is covered a partial region of the die to 405 expose the pluralityof electrical contacts 408. In one embodiment, the electrical contacts408 are metal alloy, for example Ti/Cu alloy formed by sputtering and/orCu/Ni/Au alloy formed by electroplating. A protective layer 411 iscovered the plurality of electrical contacts 408 and the dielectriclayer 410 to expose the electrical contacts 408 for allowing conductiveballs 407 electrically coupling with the print circuit board (PCB) orexternal parts (not shown). In one preferred embodiment, the material ofthe protective layer 411 comprises BCB, SINR (Siloxane polymer), epoxy,polyimides or resin. A backside surface of the die 405 is directlyadhered on a substrate 402 through an adhesive layer 404 and a firstbuffer layer 403 is formed on the substrate 402 and adjacent to the die405. For example, the substrate 402 comprises silicon, glass, alloy 42,quartz or ceramic.

Moreover, the first buffer layer 403 comprises silicone rubber BCB, SINR(Siloxane polymer), epoxy, polyimides or resin.

The substrate 402 is configured over a second buffer layer 401 such thatthe second buffer layer 401 substantially encompasses the wholesubstrate 402 due to the slope sidewall slots 409 to decrease damage tothe substrate 402 when the side of the substrate 402 is collided with anexternal object or applied by an external force, shown as FIG. 4.Therefore, the reliability and the life time of the semiconductor deviceprotective structure 400 of the present invention will be increased.Especially, when the second buffer layer 401 encompasses the wholesubstrate 402. In one case, the slope sidewall slots 409 can be etchedby wet etching or other controllable dry etching and chemical erosion.The depth of the slope sidewall slot 409 is substantially the same withthe thickness of the substrate 402.

In one preferred embodiment, the material of the second buffer layer 401comprises silicone rubber BCB, SINR (Siloxane polymer), epoxy,polyimides or resin.

Hence, according to the present invention, the aforementionedsemiconductor device protective structure has the advantages that theprotective structure of the present invention may avoid the die orsubstrate from cracking by the buffer layer substantially encompassingthe die or substrate to decrease damage to the die or substrate when theside of the die or substrate is applied by an external force.

Although specific embodiments have been illustrated and described, itwill be obvious to those skilled in the art that various modificationsmay be made without departing from what is intended to be limited solelyby the appended claims.

1. A method for manufacturing a semiconductor device protectivestructure, comprising: providing a plurality of dice with a plurality ofconductive balls formed thereon; adhering said plurality of dice over asubstrate; forming a first buffer layer over said substrate and adjacentto said dice to expose said plurality of conductive balls; removing apartial of said substrate to form a plurality of slots and substantiallyaligned to said first buffer layer; and forming a second buffer layerover said substrate and filled with said plurality of slots.
 2. Themethod in claim 1, wherein said substrate comprises silicon wafer,glass, alloy 42, quartz or ceramic.
 3. The method in claim 1, whereinthe material of said first buffer layer and said second buffer layercomprise silicone rubber BCB, SINR (Siloxane polymer), epoxy, polyimidesor resin.
 4. The method in claim 1, wherein said step of removing apartial of said substrate is performed by sawing or etching.
 5. Themethod in claim 1, further comprising a step of sawing or etching saidsubstrate along about the substantially center of said slots into aplurality of individual semiconductor devices protective structure. 6.The method in claim 1, wherein said slots includes slope sidewall slots.7. The method in claim 6, wherein a depth of said slop sidewall slot issubstantially the same with a thickness of said substrate.
 8. A methodfor manufacturing a semiconductor device protective structure,comprising: providing a substrate having a plurality of dice with aplurality of conductive balls formed thereon; removing a backsidesurface of partial said substrate to form a plurality of slots; andforming a buffer layer over said substrate and filled within saidplurality of slots.
 9. The method in claim 8, wherein said substratecomprises silicon wafer.
 10. The method in claim 8, wherein the materialof said buffer layer comprises silicone rubber BCB, SINR (Siloxanepolymer), epoxy, polyimides or resin.
 11. The method in claim 8, whereinsaid step of removing said backside surface of partial said substrate isperformed by sawing or etching.
 12. The method in claim 8, furthercomprising a step of sawing or etching said substrate along about thesubstantially center of said slots into a plurality of individualsemiconductor devices protective structure.